T-nut for 20x20 or 20x40 V-Slot aluminum extrusion (6 mm gap) compliant with original metal T-nut but adopted for M3 nut.
Fits for most of the printers based on V-Slot, e.g. Creality (CR-10, Ender 3), Tevo (Tarantula, Tornado) or Tronxy (X1, X3, X5S)
Put it in the profile slot and turn the screw - it will turn and find its locking position.
Check out my other designs:
A decent set of M3 hex bolts and nuts can be found on Banggood:
Print very slow around 10 mm/s with a little (if single nut) or no cooling (batch) ideally with PETG or ABS, as those are not so brittle as PLA.
For best results and strength set in Cura:
Top Layers: 1000
Bottom Layers: 0
Top/Bottom Pattern: Concentric